130 Yamaha low rpms

[Kmx]

Hello
I have a mid 90's 130 Yamaha saltwater series on a 24' work skiff. Compression is 130-140 on all 4. Cranks good runs smooth. Can get only 5000 rpm at wot jacked and trimmed fully. Have tried a 17, a 16, and a worn out 15 pitch props, no change in rpm.
Carbs rebuilt,new fuel pump, new fuel lines,new primer bulb, tank cleaned,new water separating filter, new plugs, tank pickup checked.
When engine trimmed too high it will hit the Rev limiter.
Could it be the power pack or coils?
Thank you for any help

 

[ClassicAQ]

Should be an increase in rpms as you decrease the pitch. Given that you haven't when dropping 2" pitch, I'd suspect an issue with your tachometer. At the very least there should be a noticeable change with how much quicker the rpms spin up with the 15". Top end WOT range for your motor is 5500...so at most you could drop 2" to reach this top end. However, it's highly unlikely you'll see a change in mph (if that was your hope with increasing rpms). And worthy to note, I assume the hull is fairly heavy given it's used as a work skiff, so I'd doubt you could get better performance by adding 500rpms with this 130hp hanging on a 24' hull.